The testis is not the major source of circulating follistatin in the ram

Abstract

The aims of this study were to determine the plasma concentrations of follistatin in rams and to assess if the testis contributes to circulating follistatin and if there is uptake or production of follistatin by the head in rams. Catheters were inserted in the carotid artery, jugular vein and spermatic vein of intact rams during the non-breeding season (experiment 1; n = 5) and breeding season (experiment 2; n = 4). In experiment 1, blood samples were collected from 5 rams every 10 min for 4 h, commencing 20-60 min after surgery. After 2 h of sampling 1 μg gonadotrophin-releasing hormone (GnRH) was injected intravenously. In experiment 2, blood samples were collected from 4 of the rams used ..